Facility security and more particularly security for facilities with free public access has always been of paramount importance to government, corporations and individuals alike. Theft, burglary, industrial espionage and an increasingly sophisticated criminal environment have made securing facilities far more difficult than at any other time in history. Law enforcement officials find themselves overwhelmed and unable to protect the average citizen from the ever increasing incidence of criminal activity. It is becoming apparent that traditional security devices such as alarms, keys, touch-pads with personal identification numbers (PIN), magnetic card readers, ID cards with two-dimensional bar-codes, radio frequency ID tags and other conventional technologies are becoming less effective in preventing access to facilities by unauthorized personnel. The problem is costing insurance companies, businesses and U.S. citizens, billions of dollars each year. In addition, many burglaries are responsible for the loss of life of many hapless victims who were attempting to protect their property. In recent years, corporations and private individuals have attempted to answer this daunting challenge by introducing a number of improved security upgrades, such as advanced smart-cards, sophisticated networked alarm systems, video surveillance and biometric identification techniques (recognizing an individual based on a physiological metric), however, although very promising, biometric security systems have yet to be broadly commercialized either due to their complexity, invasiveness or high cost.
There exists many methods for controlling access to secure facilities as described in detail herein above. Similarly there exists many methods for the biometric identification of humans which includes fingerprint pattern matching, voice recognition, iris scanning, retina imaging as well as facial image verification.
Iris and retina identification systems are considered “invasive”, expensive and not practical for applications where limited computer memory storage is available. Voice recognition is somewhat less invasive, however it is cost prohibitive and can require excessive memory storage space for the various voice “templates” and sophisticated recognition algorithms. In addition, identification processing delays can be excessive and unacceptable for many applications.
Fingerprint recognition systems, although highly accurate, are a cause of concern for many individuals due to the fact the “taking” of fingerprints is generally associated with some type of criminal activity. Fingerprints are typically associated with law enforcement and therefore have a societal stigma attached to them which makes the fingerprint biometric less desirable for general security applications. Fingerprint recognition systems therefore could meet significant resistance from the general public preventing widespread use.
Face recognition is a minimally invasive biometric technique capable of positively identifying an authorized individual. A face verification system utilizing a video camera and associated digitizer electronics can be embedded directly into a smart-card and can be constructed in such a way that its use is transparent to the user. With recent advancements in the speed of microprocessors and a notable increase in the memory capacity of inexpensive smart-cards, it has become possible to implement a practical and cost effective facial image verification system for use in providing access control to secure facilities. In addition, the present invention can also be utilized for myriad other security applications such as preventing fraud in point of sale and Internet-based financial transactions.
The prior references are abundant with biometric verification systems that have attempted to identify an individual based on a whole or partial digitized facial image. A major problem that has been recognized implicitly or explicitly by many prior reference inventors is that of securing adequate memory capacity for storing an encoded representation of a person's face on a medium that is compact and inexpensive such as a smart-card. Because of this and other limitations, none of the prior references provide suitable means for use with the present invention. Notable among the prior reference patents pertaining to facial image recognition:
U.S. Pat. No. 3,805,238, wherein Rothfjell teaches an identification system in which major features (e.g. the shape of a person's nose in profile) are extracted from an image and stored. The stored features are subsequently retrieved and overlaid on a current image of the person to verify identity.
U.S. Pat. No. 4,712,103, wherein Gotanda teaches, inter alia, storing a digitized facial image in a non-volatile ROM on a key, and retrieving that image for comparison with a current image of the person at the time he/she request access to a secured area. Gotanda describes the use of image compression, by as much as a factor of four, to reduce the amount of data storage capacity needed by the ROM that is located on the key.
U.S. Pat. No. 4,858,000 wherein Lu teaches an image recognition system and method for identifying ones of a predetermined set of individuals, each of whom has a digital representation of his or her face stored in a defined memory space.
U.S. Pat. No. 4,975,969, wherein Tal teaches an image recognition system and method in which ratios of facial parameters (which Tal defines a distances between definable points on facial features such as a nose, mouth, eyebrow etc.) are measured from a facial image and are used to characterize the individual. Tal, like Lu in U.S. Pat. No. 4,858,000, uses a binary image to find facial features.
U.S. Pat. No. 5,031,228, wherein Lu teaches an image recognition system and method for identifying ones of a predetermined set of individuals, each of whom has a digital representation of his or her face stored in a defined memory space. Face identification data for each of the predetermined individuals are also stored in a Universal Face Model block that includes all the individual pattern images or face signatures stored within the individual face library.
U.S. Pat. No. 5,053,603, wherein Burt teaches an image recognition system using differences in facial features to distinguish one individual from another. Burt's system uniquely identifies individuals whose facial images and selected facial feature images have been learned by the system. Burt's system also “generically recognizes” humans and thus distinguishes between unknown humans and non-human objects by using a generic body shape template.
U.S. Pat. No. 5,164,992 wherein Turk and Pentland teach the use of an Eigenface methodology for recognizing and identifying members of a television viewing audience. The Turk et al system is designed to observe a group of people and identify each of the persons in the group to enable demographics to be incorporated in television ratings determinations.
U.S. Pat. No. 5,386,103, wherein Deban et al teach the use of an Eigenface methodology for encoding a reference face and storing said reference face on a card or the like, then retrieving said reference face and reconstructing it or automatically verifying it by comparing it to a second face acquired at the point of verification. Deban et al teach the use of this system in providing security for Automatic Teller Machine (ATM) transactions, check cashing, credit card security and secure facility access.
U.S. Pat. No. 5,432,864, wherein Lu et al teach the use of an Eigenface methodology for encoding a human facial image and storing it on an “escort memory” for later retrieval or automatic verification. Lu et al teach a method and apparatus for employing human facial image verification for financial transactions.
Although many inventors have offered myriad approaches attempting to providing inexpensive, minimally invasive, and compact facial image verification systems in which digitized faces of human users could be stored, retrieved and compared at some later time to verify that a human user is indeed a properly authorized user, none have succeeded in producing a system that is practical and desirable for use in providing non-invasive biometric security for appropriate for use with a smart-card. Because of these and other significant limitations, no commercially viable biometric-based smart-card security system has been successfully marketed.
The present invention overcomes all of the aforesaid limitations by combining new inexpensive single integrated circuit video cameras utilizing minimal optics, with streamlined verification algorithms and advanced microprocessor architectures. The most novel aspect of the present invention, which provides biometric verification completely transparent to the user, is the integration of the video camera and associated digitizer directly into a smart-card. The video camera is embedded in the smart-card's plastic enclosure and arranged so as to provide a good quality facial image of a human user when the card is inserted into a properly designed docking station. Thus a digitized facial image can be acquired during routine use of the present invention without requiring an attentive action by the human user and is therefore minimally invasive. In addition, the algorithms of the present invention have been optimized to allow the storage of digitized facial images directly within the smart-card itself, thus the database for each human user is maintained within each individual smart-card.
Another unique feature of the present invention that helps to overcome the storage limitations of most smart-cards is the automatic removal of facial images that are no longer utilized by the system for recognition of the human user. For example, if a particular reference facial image stored on the card is never utilized for verification, after a predetermined time limit, the facial image would automatically be removed from the system thus freeing up storage space for newer images or other essential data.